Dipsticks can be used to measure the quantity of liquid in an otherwise inaccessible space, by inserting and removing the stick and then checking the extent to which it is covered by the liquid. The most familiar example is the oil level dipstick found on most internal combustion engines.
Some dipsticks can be locked into position. But, frequently, the lock is not visible and/or can have multiple assembly orientations.
Generally, a need exists for improved dipstick assemblies that are able to measure fluid levels in a more reliable manner over the life of the assembly. Further a need exists for a dipstick with a visual, positive, accurate and reliable indication that the dipstick is securely in place.